Planet-9 Porsche Forum banner

1 - 18 of 18 Posts

·
Registered
Joined
·
85 Posts
Discussion Starter #1
I am guessing the GTS would be faster because of the PDK. Porsche has the GTS only .1 second behind the GT4 in 0-60. Pretty close for autocross, considering the GTS can downshift just about seamlessly. I will find out soon enough if all goes well. My personal goal is to post better times against known drivers than I currently do in my GT3RS.:dance:

It is not enough that I win. They must loose.
I did not come up with that.
 

·
Registered
Joined
·
346 Posts
When 2nd gear goes to 80 MPH, how much shifting are you actually doing in a manual? I have the PDK and I just let it do its thing in AX while in Sport mode. Depending on the course and driver, I can beat a GT3 but I never ran against a RS. Good luck with that.
 

·
Registered
Joined
·
85 Posts
Discussion Starter #3
I am not thinking about my GT3 RS against either one. Just guessing that the ability of the PDK to stay in the sweet spot will be an advantage. Our current venue has some defects and new restricted areas that add some sharp slow turns often with quick transitions just before same. That would like a lower gear to gain speed back but would also require a downshift in what amounts to be a tight slalom.
 

·
Registered
Joined
·
603 Posts
If you're posting close times now then PDK could give an edge. Most of my AX's I've beaten PDK cars in a 6MT.

AX is quite unique in that you have such a limited amount of time to learn the course and make improvements. Between two matched drivers then transmission could make a difference, but I would think the suspension and tires would be more significant.
 

·
Registered
Joined
·
948 Posts
Tires are the only thing holding back the GTS equipped with PDK/X73/PTV. The semi-race tires (MPSC2s or Dunlop Sport Maxx Race) on the GT4 are out-of-this-world grippy.
 

·
Registered
Joined
·
154 Posts
These videos give you and idea of the performance differences with OEM rubber.


 

·
Registered
Joined
·
85 Posts
Discussion Starter #7
Good find. The GTS hold its own pretty good in the lower gears. It looks like it would have an advantage in autocross because it would run a course in 2nd and 3rd seamlessly shifting to keep the boil on.
Sadly, I will not be able to run a GTS PDK against a GT4. I tried to buy one last week from an out of state dealer. Made the mistake of going through my dealer and they were told that to get that car they would also need to buy a dead inventory car as well. That told me that the car would sell over list to an out of state customer.
 

·
Registered
Joined
·
319 Posts
IMO, you are comparing apples to oranges. Do you want a street car or a track car?
The GTS model is a street car.
The GT4 model is a track car!

Differences? GT4 3.8L gives more torque, GT3 suspension lowered with adjustable sway, added aero downforce, etc ... all setup for the track.
 

·
Registered
Joined
·
85 Posts
Discussion Starter #9
I am thinking of autocross only where the PDK could tip the scale in its favor. For sure the GT4 will be much better on a track and mine will see that next season.
 

·
Registered
Joined
·
319 Posts
I agree with you there. If you want a street car and autocross only, then GTS with PDK is the way to go.
The PDK is a huge benefit for easy quick shifting. The MT while has great driving feel is lousy for downshifting into and out of 2nd.
When I track my car, I tend to shift as infrequently as possible.
 

·
Registered
Joined
·
583 Posts
Not enough shifting in a typical AX to give the PDK an advantage IMO. On identical tires I give the nod to the lighter weight car with more sophisticated suspension setup and negative camber to make the most of their contact patch. GT4

On different tires, the car with sticky tires wins.
 

·
Registered
Joined
·
1,483 Posts
Remove the wing on the GT4 to reduce drag for auto-x. In all seriousness, whichever car has the best alignment and tires will win.
 

·
Registered
Joined
·
183 Posts
On equal tires a PDK GTS could give a GT4 a run for its money, but not for the reason you'd think.

At the autocross last weekend I was grabbing 1st as many as three times in my GT4. I (and PDK cars) settled on once as the fastest, but sport plus with the auto-blip makes it easy to grab 1st whenever and wherever you chose- quick enough that many assumed I had PDK. The downshift came under braking, in-plane shift, and I'd contend I was losing zero time there. I'll grant you that I lost a fraction on the two upshifts, but I'll also contend the manual's 66 fewer pounds made up for this elsewhere.

Walter Röhrl says on the average track he's a half second slower in the manual, most drivers would be a second. An average autocross has just a couple shifts, however...

That said, at an autocross I do think PDK is a significant advantage for one simple reason: gearing. 2nd gear is a full 17% taller in the manual than the PDK, meaning you're averaging that amount less torque through that gear. Given that the GT4's power advantage over a GTS is only 13%, and that most autocrosses are conducted almost exclusively in 2nd gear, that's huge.
 

·
Registered
Joined
·
948 Posts
I am really looking forward to driving my GT4 on same track as I drove the GTS next month (NOLA). So, I can make a similar video and see how it does in comparison. NOLA has a few tight corners where PDK is quicker, but it also has some really fast and long sweepers where the GT4 is incredibly fast. If I have the balls to keep the pedal down during those sweepers, I hope to find 14 seconds on my best lap time- 2:14 to 2:00.
 

·
Registered
Joined
·
583 Posts
That said, at an autocross I do think PDK is a significant advantage for one simple reason: gearing. 2nd gear is a full 17% taller in the manual than the PDK, meaning you're averaging that amount less torque through that gear. Given that the GT4's power advantage over a GTS is only 13%, and that most autocrosses are conducted almost exclusively in 2nd gear, that's huge.
Got a link for that gearing difference? Last post I saw showed a top speed in 2nd nearly identical at 76 mph for both 6 spd and PDK 981.
 

·
Registered
Joined
·
583 Posts
Look for actual GPS logged speeds at redline as I believe 2nd is very close between the two cars. Maybe 2-3 mph according to R&T ??

from an earlier thread:
"Emailed Porsche directly. Official response:

Thank you for your email, the final drive ratios you have quoted are correct if I can clarify what ratio is for what car.

981, 981S, 981 GTS manual has a final drive ratio of 3.889.
981, 981S, 981 GTS PDK has a final drive ratio of 3.25
991 manual has a final drive ratio of 3.444
991 PDK has a final drive ratio of 3.44
991S manual has a final drive ratio of 3.44
991S PDK has a final drive ratio of 3.44

I hope this helps you"
 

·
Registered
Joined
·
183 Posts
I looked up the gear ratios per another Porsche source and I believe you're correct- the sheet I linked to has a typo. As you state above the PDK gets a 3.25:1 ring and pinion, and this cancels out the PDK's lower 2nd gear ratio- the PDK is actually almost 2% taller. So ignore the bit about gearing- all else equal my money's on the manual an its 66 lb advantage on the autocross, and that's before engine and suspension. Given that I don't think a GTS will catch a well driven GT4 even if they are on the same tires, PDK or no.
 
1 - 18 of 18 Posts
Top